Gregory of Nazianzus and Atheism

That God, the creative and sustaining cause of all, exists, sight and
instinctive law inform us - sight, which lights upon things seen as nobly fixed
in their course, borne along in, so to say, motionless movement; instinctive
law, which infers their author through the things seen in their orderliness. How
could this universe have had foundation or constitution, unless God gave all
things being and sustains them? No one seeing a beautifully elaborated lyre with
its harmonious, orderly arrangement, and hearing the lyre’s music will fail to
form a notion of its craftsman-player, to recur to him in thought though
ignorant of him by sight. In this way the creative power, which moves and
safeguards its objects, is clear to us, though it be not grasped by the
understanding. Anyone who refuses to progress this far in following instinctive
proofs must be very wanting in judgment.

On God and Christ, p. 41

Gregory N’s comments of course echo the words of the apostle Paul:

What can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely his eternal power and divine nature, have
been clearly perceived, ever since the creation of the world, in the things that
have been made. So they are without excuse. For although they knew God, they did not honour hum as God or give thanks to him, but they became futile in their
thinking, and their foolish hearts were darkened. Claiming to be wise, they
became fools.

Romans 1.19-22 (ESV)

Gregory N. also points out the implications of atheism (and polytheism):

The opinions about deity that hold pride of place are three in number: atheism,
polytheism, and monotheism. Let the game go on! Atheism with its lack of a
governing principle involves disorder. Polytheism, with a plurality of such
principles, involves faction and hence the absence of a governing principle, and
this involves disorder again. Both lead to an identical result - lack of order,
which in turn leads to disintegration, disorder being the prelude to
disintegration.

On God and Christ, p. 70

Gregory doesn’t specify to what he his referring when he writes of disorder and disintegration, but it can be taken in the widest sense - the universe, society, individual life. The solution, of course, is Trinitarian monotheism:

Monotheism, with its single governing principle, is what we value - not
monotheism defined as the sovereignty of a single person (after all,
self-discordant unity can become a plurality) but the single rule produced by
equality of nature, harmony of will, identity of action, and the convergence
towards their source of what springs from unity - none of which is possible in
the case of created nature. The result is that though there is numerical
distinction, there is no division in the substance. For this reason, a one
eternally changes [perhaps a slightly misleading word here] to a two and stops
at three - meaning the Father, the Son, and the Holy Spirit.

On God and Christ, p. 70

A Warning from Gregory of Nazianzus

Gregory writes against the Eunomians, who held that God the Father and God the Son were different in substance, on the basis that the Father is pure agency, of whom the Son is the supreme offspring and product and perfect image. He is not of the divine subtance, because that is unique and belongs to the Father alone, substance for them being underived reality. Given the frequency with which we discuss theology amongst ourselves, and the ease with which we can publish our reflections on the interweb, we would do well, I think, to listen to and ponder his warning to the Eunomians in his First Theological Oration (Oration 27), An Introductory Sermon against the Eunomians.

Discussion of theology is not for everyone, I tell you, not for everyone -
it is no such inexpensive or effortless pursuit. Nor, I would add is it for
every occasion, or every audience; neither are all its aspects open to inquiry.
It must be reserved for certain occasions, for certain audiences, and
certain limits must be observed. It is not for all people, but only for those
who have been tested and have found a sound footing in study, and, more
importantly, have undergone, or at the very least are undergoing, purification
of body and soul. For one who is not pure to lay hold of pure things is
dangerous, just as it is for weak eyes to look at the sun’s brightness.

What is the right time? Whenever we are free from the mire and noise
without, and our commanding faculty is not confused by illusory, wandering
images, leading us, as it were, to mix fine script with ugly scrawling, or
sweet-smelling scent with slime. We need actually “to be still” in order to know
God, and when we receive the opportunity “to judge uprightly” in
theology.

Who should listen to discussions of theology? Those for whom it is
a serious undertaking, not just another subject like any other for entertaining
small talk, after the races, the theatre, songs, food and sex: for there are
people who count chatter on theology and clever deployment of arguments as one
of their amusements.

What aspects of theology should be investigated, and to what limit?
Only aspects within our grasp, and only to the limit and experience and capacity
of our audience. Just as excess of sound or food injures the hearing or general
health, or, if you prefer, as loads that are too heavy injure those who carry
them, or as excessive rain harms the soil, we too must guard against the danger
that the toughness, so to speak, of our discourses may so oppress and overtax
our hearers as actually to impair the powers they had before…

On God and Christ (St. Vladimir’s Seminary Press) pp.
26-27

Some questions we should therefore ask ourselves when we discuss theology:

How is my growth in holiness at the moment?
Is this a subject which I actually know something about?
Am I free from distractions, without and within, that I may reflect on what I am discussing?
Is this discussion going to be taken seriously and have an impact on our knowledge and love of God, and our discipleship, or will it merely function as a form of entertainment for speakers and hearers?
Will this discussion be of an appropriate nature for the company in which it is taking place?